V30: Trim generated proven appendix EOF

Normalize the canonical proven appendix renderer so promotion-generated markdown ends with exactly one trailing newline and no blank EOF line. Apply the same behavior to the demonstration renderer and cover it with the proven generator test.

Proof:

- node --test --test-force-exit protocol-demonstration/test/proven-generator.test.js

- git diff --check

- node scripts/generate-bitcode-proven.mjs --version V30 --commit 9d0adf7 --worktree-state clean --allow-dirty --stdout > /tmp/BITCODE_SPEC_V30_PROVEN.md && node -e "const fs=require('fs'); const s=fs.readFileSync('/tmp/BITCODE_SPEC_V30_PROVEN.md','utf8'); if(!s.endsWith('\n')||s.endsWith('\n\n')) process.exit(1);"

Author: geraldarthurdavis

packages/protocol/src/canonical/proven-generator.js

@@ -7126,7 +7126,9 @@ export function renderCanonicalProvenMarkdown(data) {
       ])
     ));
   }
-  lines.push('');
+  while (lines[lines.length - 1] === '') {
+    lines.pop();
+  }
   return `${lines.join('\n')}\n`;
 }
 

protocol-demonstration/src/canonical/proven-generator.js

@@ -7124,7 +7124,9 @@ export function renderCanonicalProvenMarkdown(data) {
       ])
     ));
   }
-  lines.push('');
+  while (lines[lines.length - 1] === '') {
+    lines.pop();
+  }
   return `${lines.join('\n')}\n`;
 }
 

protocol-demonstration/test/proven-generator.test.js

@@ -48,6 +48,8 @@ test('canonical proven generator renders a stable appendix from seeded proof run
   assert.ok(markdown.includes('## Run Details'));
   assert.ok(markdown.includes('`prompt-completeness`'));
   assert.ok(markdown.includes('_legacy/ENGI_SPEC_V15_PROVEN.md'));
+  assert.match(markdown, /\n$/);
+  assert.doesNotMatch(markdown, /\n\n$/);
 });
 
 test('canonical proven generator fails closed on proof-family catalog drift across runs', () => {